textproduct: Albany

WHAT HAS CHANGED

Winter Weather Advisories have been cancelled for the eastern Catskills, Mohawk Valley, and portions of the Greater Capital District as only patchy freezing drizzle continues this morning. A special weather statement continues this morning for the potential of black ice to develop on any untreated wet pavement surfaces.

A Winter Storm Watch has been issued for northern Warren county Friday morning through Saturday morning for impactful winter conditions for the Friday evening commute.

KEY MESSAGES

1) A weather system arrives from the southwest bringing medium to high chances for mixed precipitation and snow to eastern New York and western New England Friday into Saturday.

2) Continuing to monitor an off-shore coastal low Sunday night into Monday. Forecast guidance remains steady for low chances of light snow south of I-90.

DISCUSSION

KEY MESSAGE 1... Latest high resolution model guidances and ensemble forecast model guidances are in agreement for a low pressure system to move through the Great Lakes region and bring an occluded front through eastern New York and western New England Friday into Saturday. There is disagreement on when precipitation arrives (start timing) as the front arrives, dry air will battle the moisture associated with this system so there could be a delay on when precipitation begins. The current forecast supports onset timing between late Friday morning and early afternoon. Outside of southern Vermont and the southern Adirondacks, precipitation is likely to begin as a wintry mix of rain, freezing rain, and snow. Temperatures are going to contribute greatly to the type of precipitation during the late afternoon and evening hours. If temperatures hover around and above freezing, freezing rain and rain is likely across locations south of I-90 before transitioning over to snow/sleet during the early evening hours as they fall below freezing. For locations north of I-90, a mix of rain and snow is likely before transitioning over to all snow for Friday evening. An important forecast note is that the Great Capital District region and Mid-Hudson Valley could become dry slotted by Friday evening for the best case scenario of low precipitation amounts, in both ice and snow. The eastern Catskills and Mohawk Valley have the highest probabilities to see between 0.1 and 0.25 inches of ice accumulations as temperatures contribute to a longer period of a wintry mix during the afternoon and early evening hours. Precipitation chances decrease for Saturday morning and afternoon for lingering light snow showers before drier conditions return Saturday night.

This is a low confidence forecast for locations outside of the southern Adirondacks and southern Vermont as temperatures, precipitation amounts, and precipitation types continue to fluctuate with each forecast model run. Continue to monitor the latest forecasts and be prepared for slippery/slick driving conditions Friday evening.

Latest National Blend of Models 4.3 probabilistic data for 24 hour snowfall amounts greater than 7 inches is between 65 and 75 percent for northern Warren county in New York and 50 percent across Windham county in Vermont. Elsewhere, probabilities are less than 45 percent at this forecast period. With confidence increasing in impactful snow amounts, mixed precipitation amounts, and with collaboration of neighboring offices and the weather prediction center winter desk, a Winter Storm Watch has been issued for northern Warren county from Friday morning through Saturday morning. Hazardous driving conditions due to a combination of mixed precipitation and snow could occur for the Friday evening commute, especially along I-87 in northern Warren county.

KEY MESSAGE 2... Ensemble forecast model guidances continue to be in good agreement for a coastal low storm to develop off the Atlantic coast. The latest forecast supports a track for the center of the low to stay off-shore. This brings low chances for light snowfall across locations south of I-90. If the track of the low moves further inland, we could see higher chances of light snow. If it moves further out to sea, we'll see even lower chances. Forecast models continue to fluctuate on exactly where the track of the low will go. But, the latest forecast continues to support low chances of minor impacts to travel for Monday morning with light snow amounts south of I-90. Continue to monitor latest forecasts as we get closer in time.

AVIATION /12Z THURSDAY THROUGH MONDAY/

Through 12Z/Friday, mainly VFR conditions are expected at the TAF sites through the period, despite persistent Cigs of 4000-7000 FT AGL. Some occasional MVFR Cigs may develop after 21Z/Fri at KPSF. Also, some light snow could develop at KPOU after 10Z/Fri along with MVFR Vsbys/Cigs.

North to northeast winds at 4-8 KT this morning, becoming light/variable this afternoon and tonight at less than 5 KT, except becoming southeast at 5-10 KT at KALB and KPSF after midnight.

Outlook...

Friday Night: High Operational Impact. Definite RA...SN. Saturday: Moderate Operational Impact. Chance of SN. Saturday Night: Moderate Operational Impact. Chance of SN. Sunday: Moderate Operational Impact. Chance of SN. Sunday Night: Moderate Operational Impact. Chance of SN. Monday: Moderate Operational Impact. Chance of SN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...Winter Storm Watch from Friday morning through Saturday morning for NYZ042. MA...None. VT...None.